LOW COST AND FIRST TIME EVER AUTOMATIC WATER LEVEL CONTROL FOR DOMESTIC OR INDUSTRIAL APPLICATIONSPROJECT SUCCESSFULLY DONE BY AHASAN ULLAH HASAN

LOW COST AUTOMATIC WATER LEVEL CONTROL FOR DOMESTIC APPLICATIONS A Thesis submitted in partial fulfillment of the requirements for the Diploma in “Electrical Engineering” By AhasanUllahHasanRoll: 547106 Reg: 448448

Under guidance of Dr. S. GOPALAKRISHNA Department of Electrical Engineering Daffodil Institute Of IT, ChittagongJuly-2015

DEPARTMENT OF ELECTRICAL ENGINEERING

CERTIFICATEThis is to certify that the thesis entitled “Low Cost Water Level

Control for Domestic and Industrial Applications”, submitted

by AhasanUllahHasanwith his group is in partial fulfillment of

the requirements for the Diplomain Electrical Engineering

during session 2010-2011 at Daffodil Institute of IT,Chittagong

bonafide record of research work was carried out by them under

AhasanUllahHasan.

The candidates have satisfied all the prescribed requirements.

The Thesis which is based on candidates’ self work, have not

submitted elsewhere for a degree/diploma.

In my opinion, the thesis is of standard required for the award of a

Diploma in Electrical Engineering.

Place: Chittagong

Dept. of Electrical Engineering

Kamal Uddin

Daffodil Institute of IT

ACKNOWLEDGEMENTSFirst and foremost, we would like to thank our supervisor of this project, MD Kamal Uddin Sir for valuable guidance and advice. He guided us greatly to work in this project. His willingness to motivate us helped tremendously. Next we thank Ikram Sir, for without his helping hand the project would be incomplete. Besides, we would like to thank the authority of DIIT, Chittagong for providing us with a good environment and facilities to complete this project. It gave us an opportunity to participate and learn about the operation of Water Level Controller. Finally, an honorable mention goes to our families and friends for their understanding and support in completing this project. Without help of those mentioned above, this project could not have been completed.

Ishwar Chandra Murmu

Laloo Kumar Yadav

B.Tech (Electrical Engineering) b

Dedicated to The Almighty of Allah, Mohammad (S.M) and Our Parents

ABSTRACTThe drinking and using of water crisis in Bangladesh and along

all over the world is reaching alarming proportions. It might very

soon attain the nature of global crisis. Hence, it is of utmost

importance to preserve water. In many houses there is unnecessary

wastage of water due to overflow in Overhead Tanks. Automatic

Water Level Controller can provide a solution to this problem.

The operation of water level controller works upon the fact that

water conducts electricity. So water can be used to open or close a

circuit. As the water level rises or falls, different circuits in the

controller send different signals. These signals are used to switch

ON or switch OFF the motor pump as per our requirements. ii

CONTENTS Abstract i Contents ii List of Figures ivList of Tables v Abbreviations and Acronyms viCHAPTER 1 INTRODUCTION 1.1 Motivation 2 1.2 Thesis Objectives 2 1.3 Organization of Thesis 3

CHAPTER 2 SYSTEM COMPONENTS 2.1 Introduction 5 2.2 Components used 5 2.2.1 Metallic Contacts 6 2.2.2 Transformer 6 2.2.3 Full-wave Rectifier 7 2.2.4 Voltage Regulator IC 8 2.2.5 Centrifugal Submersible Pump 9 2.2.6 Relay 10 2.2.7 NAND Gate 11 2.2.8 555 Timer IC 13 iii

2.2.9 Transistor 14 2.2.10 Light Emitting Diode 15 2.2.11 Voltage Divider Circuit 15 2.3 Circuit Diagram 16 2.4 Circuit Layout 17 2.5 Complete Hardware Setup 18 2.6 Conclusion 18

CHAPTER-3 LOGIC AND BASIC OPERATION 3.1 Step-by-step Operation 20 3.2 Truth Table of Water Level Controller 21

3.3Advantages of proposed water level controller 22 3.4 Cost Estimation 23 CHAPTER-4 CONCLUSION AND FUTURE WORK 4.1Results 25 4.2Conclusion 25 4.3Future Work 25 References 26 iv

LIST OF FIGURES Fig. No Name of the Figure Page. No. 2.1 L-shaped Metallic Contacts 6 2.2 Centre-tap step down Transformer 6 2.3 Full Wave Rectifier with Voltage Regulators 8 2.4 Centrifugal Submersible Pump 9 2.5 Relay Terminal Layout 10 2.6 NAND Gate 11 2.7 Pin Configuration of 74F00 Quad 2-Input NAND Gate 12 2.8 Logic Diagram of 74F00 Quad 2-Input NAND Gate 12 2.9 555 Timer in Bi-Stable Mode 13 2.10 555 Timer Waveforms 13 2.11 C547 Transistor 14 2.12 Light Emitting Diode 15 2.13 Voltage Divider Circuit 15 2.14 Schematic Diagram of Water Level Controller 16 v

LIST OF TABLES Table. No. Name of the Table Page. No. 2.1 Truth Table of NAND gate 11

3.1 Truth Table of Water Level controller 21 vi

ABBREVIATIONS AND ACRONYMS

UGT - Under Ground Tank

OHT - Overhead Tank

IC - Integrated Circuit

MC- Magnetic Contractor

SPDT - Single Pole Double Throw

NO - Normally Open

NC - Normally Closed

COM - Common

LED - Light Emitting Diode 1

CHAPTER1 Introduction2

1.1 MOTIVATION:

The total amount of water available on Earth has been estimated at 1.4

billion cubic kilometers, enough to cover the planet with a layer of

about 3 km. About 95% of the Earth's water is in the oceans, which is

unfit for human consumption. About 4% is locked in the polar ice

caps, and the rest 1% constitutes all fresh water found in rivers,

streams and lakes which is suitable for our consumption. A study

estimated that a person in India consumes an average of 135 litters per

day.This consumption would rise by 40% by the year 2025. This

signifies the need to preserve our fresh water resources.

1.2 THESIS OBJECTIVES:

The following objectives are likely to be focused and achieved at the

end of the project.

1) To create the most cost-effective and reliable water level

controller using as less resources as possible.

2) To study the controller model and observe its characteristics.

3) To compare the controller with the conventional controllers

available in market and find the advantages of the former over

the latter.

4) To suggest any ideas or improvements that can lead to future

development of the controller.

1.3 ORGANISATION OF THESIS:

The thesis is organised into six chapters including the chapter of

introduction. Each chapter is different from the other and is described

along with the necessary theory required to comprehend it.

Chapter2 deals with the water level controller components. The circuit

diagram gives an overview of the whole system. Then, each of the

components is studied individually. Their purpose in the system is

explained along with their ratings and connections.

Chapter3 describes the basic operation of the controller. A step-by-step

analysis is presented on the actions that would take in the controller

beginning from the detection of water by the metallic contacts to the

switching ON or switching OFF of the pump accordingly. We then study

the truth table of the water level controller. It summarizes the logic

involved in the complete operation of the controller. The scenarios

occurring in the controller i.e. water being filled to the top of the OHT and

then being emptied are represented diagrammatically. Adjacently, the

change in states occurring in the different circuit elements is depicted.

Then we have a comparative study of the water level controller with

commercially available controllers. The advantages and approximate cost

of the whole apparatus were discussed.

Chapter4 concludes the work performed so far. The possible limitations in

proceeding research towards this work are discussed. The future work that

can be done in improving the current scenario is mentioned. The future

potential along the lines of this work is also discussed. 4

CHAPTER2 System Components 5

2.1 INTRODUCTION:

The water is a very important and useful for our living and daily life, We can’t

stay one more day without water. In our city and village system of Technology

the water is wasting day by day, because the are not control or using any

automatic tank controller because of high prices of water level controller, the

people of the world everyone want to save time, money and also saving water.

Using water and also saving water is a necessary part of our daily life.

The water level controller we propose to make in our project depends on two

detection points in the OHT and UGT. The water level must be controlled at

these two points. To facilitate this, we use sensors. In our case, these sensors are

using an NPN based IC with RELAY space between them present at each

detection point. When water reaches a sensor, a proper circuit must be present

such that the presence of water is detected and a signal is produced. This signal

must pass through IC to give the correct actuator output to Relay. Also it must

be strong enough to activate the Relay, relay send the Signal to control circuit,

and control circuit decide the Action to active Motor/Pump. Our circuit

essentially uses the high and low states of water lever monitoring with the LED

2.2 COMPONENTS USED:

The Water Level Controller has the following main components:-

IC – ULN2803 or ULN2804

9V Adapter

LED

Resistor

Magnetic Contactor

Relay

IC ULN 2803 Pinout& WorkingIntroduction

IC ULN2803 consists of octal high voltage, high current darlington transistor

arrays. The eight NPN Darlington connected transistors in this family of

arrays are ideally suited for interfacing between low logic level digital

circuitry (such as TTL, CMOS or PMOS/NMOS) and the higher

current/voltage requirements of lamps, relays, printer hammers or other

similar loads for a broad range of computer, industrial, and consumer

applications.

Features

Eight Darlingtons with Common Emitter.

Open–collector outputs.

Free wheeling clamp diodes for transient suppression.

Output Current to 500 mA.

Output Voltage to 50 V.

Inputs pinned opposite outputs to simplify board layout.

Pinout

Working

The ULN 2803 IC consists of eight NPN Darlington connected transistors

(often called a Darlington pair). Darlington pair consists of two bipolar

transistors such that the current amplified by the first is amplified further by

the second to get a high current gain β or hFE. The figure shown below is one

of the eight Darlington pairs of ULN 2803 IC.

Case 1: When IN is 0 volts.

Q1 and Q2 both will not conduct as there is no base current provided to them.

Thus, nothing will appear at the output (OUT).

Case 2: When IN is 5 volts.

Input current will increase and both transistors Q1 and Q2 will begin to

conduct. Now, input current of Q2 is combination of input current and

emitter current of Q1, so Q2 will conduct more than Q1 resulting in higher

current gain which is very much required to meet the higher current

requirements of devices like motors, relays etc. Output current flows through

Q2 providing a path (sink) to ground for the external circuit that the output is

applied to. Thus, when a 5V input is applied to any of the input pins (1 to 8),

output voltage at corresponding output pin (11 to 18) drops down to zero

providing GND for the external circuit. Thus, the external circuit gets

grounded at one end while it is provided +Vcc at its other end. So, the circuit

gets completed and starts operating.

9 (Nine)-volt battery

From Wikipedia, the free encyclopedia

"9-Volt" redirects here. For the WarioWare character, see 9-Volt

(WarioWare).

Duracell PP3 (9 volt) battery

The nine-volt battery in its most common form was introduced for the

early . It has a rectangular prism shape with rounded edges and a polarized

snap connector at the top. This type is commonly used in pocket radios,

paintball guns, and small electronic devices. They are also used as backup

power to keep the time in certain electronic clocks. This format is commonly

available in primary carbon-zinc and alkaline chemistry, in primary lithium

iron disulfide, and in rechargeable form in nickel-cadmium, nickel-metal

hydride and lithium-ion. Mercury oxide batteries in this form have not been

manufactured in many years due to their mercury content. This type

is  NEDA 1604, IEC 6F22 and "Ever Ready" type PP3 (zinc-carbon) or

MN1604Most nine-volt alkaline batteries are constructed of six individual

1.5V LR61 cells enclosed in a wrapper. These cells are slightly smaller

than and can be used in their place for some devices, even though they are

3.5 mm shorter. Carbon-zinc types are made with six flat cells in a stack,

enclosed in a moisture-resistant wrapper to prevent drying.

As of 2007, 9-volt batteries accounted for 4% of alkaline primary battery

sales in the US. In Switzerland as of 2008, 9-volt batteries totalled 2% of

primary battery sales and 2% of secondary battery sales. 

Other nine-volt batteries of different sizes exist, such as the British "Ever

Ready" PP series and certain lantern batteries.

Magnetic Contactor- construction & how it works.

Introduction

Magnetic contactor is not a protection device. It does not protect a circuit

under any circumstances like the circuit breaker does. The purpose of

magnetic contactor in a circuit is switching. This switching might associated

with high power handling, frequent operations etc. With magnetic contactor

we can operate motor of any rating from a distance. There are magnetic

contactor of kilo ampere range in the market.

Magnetic contactor is different from relay and circuit breaker:

Magnetic contactor is a switchgear device like a relay but it has the higher

current capacity and hence has some extra use in power circuits. Where relay

can be operated by below 1 amp, magnetic contactor may be used in over

1KA power circuits. It is made for frequent switching operation even might

be switched on & off 1000 times in a day. Hence it is mechanically robust

and strong to withstand such switching and capable of handling high power.

Magnetic contactor is the robust version of relay. Relay handles small power

for its weak contacts, but magnetic contactor can handle high power. So this

protection device can be used in power circuit. A magnetic contactor can not

actuate or operate by itself it always needed an external signal like relay. On

the other hand Circuit breaker is not made for frequent operation, but it can

operate or actuate by itself or send some signal to external circuit.

Construction of magnetic contactor:

Magnetic contactor has three parts. 1.power coil, 2.Auxiliary coil, 3.Spring

mechanism. The power coil carry high current and auxiliary contactor

receives signal to make the contactor open or close or send the status of the

contactor(on or off) to external systems like PLC, SCDA. The spring

mechanism provides mechanical force to make the contact on or off.

Enclosures are made of insulating materials like Bakelite, Nylon 6, and

thermosetting plastics to protect and insulate the contacts and to provide

some measure of protection against personnel touching the contacts.

magnetic contactor

Relay

Relays are defined as remote controlled electrical switches that are controlled by

another switch e.g. - a horn switch. Relays allow a small current flow in a circuit

to control a higher current circuit. The relay used here is a Single Pole Double

Throw (SPDT) relay whose magnetizing coil terminals operate on 6V DC

supply. It has the following terminals:

COIL- This is one end of the coil.

COIL- This is the other end of the coil. These are the terminals where we apply

voltage to in order to give power to the coils (which then will close the switch).

The polarity does not matter. One side gets positive voltage and the other side

gets negative voltage.

NO- This is Normally Open switch. This is the terminal where the device is

connected that we want the relay to activate when the relay is powered. The

device connected to NO terminal will be deactivated when the relay has no

power and will turn on when the relay receives power. We will use this terminal

for powering the pump.

NC- This is the Normally Closed Switch. This is the terminal where we connect

the device that we want powered when the relay receives no power. The device

connected to NC will be active when the relay has no power and will deactivate

when the relay receives power.

COM- This is the common terminal of the relay. When the relay is powered and

the switch is closed, COM and NO will be shorted. If the relay isn't powered

and the switch is open, COM and NC get shorted.

It is used in normally open mode. A 1N4007 diode and a 100μF capacitor are

connected in parallel to the magnetizing coil terminals. This is done because

when voltage input to the relay coil is removed and its magnetic field collapses,

a huge reverse voltage is produced. Without proper protection, this voltage will

cause the contact that is switching the relay coil to arc and will in time destroy

it.

CONCLUSION: Thus we have assembled a circuit which works on the conduction of electricity by water. This circuit works using logic gates and the output obtained is in the form of ON and OFF state of the centrifugal submersible pump.

CHAPTER3 Logic and Operation 20

INTRODUCTION: After assembling the system, what remains is to observe its operation and efficiency. This can be done by breaking down the activity of the controller from the detection of water to the working of the pump or Motor. We go over the responses obtained when water reaches the sensors and the logic employed behind it. We also try to justify how a system as simple as ours can compete with those available commercially.

This is one of the simplest water level indicator that can give up to 8 indications – Full, Half and Low water levels in the overhead tank through LED indications. The circuit is simple and uses a single IC and a few components.

The main part of the water level circuit is the 9 channel Darlington array IC ULN2804. Its seven inputs are connected to seven probes to sense the water level and the corresponding outputs are connected to three LEDs through current limiting resistors. A common probe (common) is connected to the positive rail. When this probe gets electrical continuity through water with the other probes the corresponding LEDs light.

Schematic of the Water level Indicator Circuit

ULN2804 datasheet

Here is an idea how to connect the 7 segment display.SettingsAssemble the circuit on a common PCB and enclose in a small box. This unit can be kept in a place for easy monitoring. Use brass or chromium plated pins as probes. Connect the probes with the unit using three core shield wire. Probes should be plugged into the tank through the side. The low probes in the lower position, half probes in the middle positions and high ones in two upper position. If the tank is empty, no LEDs will be on. When the water level increases the green LEDs (marked with G) will start to light up according to the H2O level. When the tank becomes full the red LEDs (marked R) will be on. In short, if Green, Yellow and Red LEDs light, tank is full.

STEP-BY-STEP OPERATION:

We placed metallic contacts both at the lower and upper area of the OHT. When water filled the gap between them, the adjoining circuit closed and a signal (current) flowed.

These signals were given to a NAND gate which produced an output signal Q.

This signal Q was used to provide Reset signal to the 555 timer IC. Also signal A was fed as the Trigger input to the 555 timer IC.

The output of the timer was passed through a NOT gate to get the desired signal for controlling the pump.

The NOT output signal was then passed through a BJT to amplify it and make it strong enough to activate the relay.

The pump was started through the relay and water was provided to the OHT. 21

Advantages of the proposed water level controller

A. Maintenance

It is an economical system that requires very less maintenance as compared to conventional system as it has no complicated circuits and delicate mechanisms. This saves the additional maintenance cost.

B. Cost

The main advantage of the water level controller is it has very low cost than the conventional one available in markets. For example, some commercial controllers use microcontrollers which alone costs around Rs.800. Some controllers even have a price range of Rs.2000-Rs. 4000. But for our system, the components used are less in number and easily available. Hence losses will be less leading to a better efficiency.

C. Construction

The construction of a water level controller is very simple as it requires only a few components. The circuit involved is also relatively simpler.

D.Skill Required

Since the system of water level controller is simpler than the ones conventionally available, it can be easily made at home. The controller can also be easily operated by anyone. On a final note, the conventional controllers in market mostly use capacitive sensors and microcontrollers. These increase the cost as well as the complexity of the system. We have developed a rather simpler but efficient model of a water level controller. 23

3.4 COST ESTIMATION OF WATER LEVEL CONTROLLER: TABLE 2: COST ESTIMATION Sr. no.

Particulars Cost in INR (approx.)

1 Metallic Contacts 2502 Adaer 1006 Relay 409 ULN2803 3510 Light Emitting Diode

Resistor105

TOTAL 440

CHAPTER4 Conclusion

Conclusion and Future Works 25

4.1 RESULTS:

The experimental model was made according to the circuit

diagram and the results were as expected. The motor pump

switched ON when the OHT was about to go dry and

switched OFF when the OHT was about to overflow.

4.2 CONCLUSION:

This system is very beneficial in rural as well as urban

areas.

It helps in the efficient utilization of available water

sources.

If used on a large scale, it can provide a major

contribution in the conservation of water for us and the

future generations.

In these days, when Earth's reserve of consumable water is

decreasing every moment, every drop has its value. Water

level controller is a simple yet effective way to prevent

wastage of water. Its simplicity in design and low cost

components make it an ideal piece of technology for the

common man.

4.3 FUTURE WORK:

The water level controller designed in this project can be

used to control water flow. However, there is no way of

knowing whether the source of water, which in this case is

the UGT, actually has water or not. If no water source is

present, then the submersible pump would start running

unnecessarily and overheat itself. This could be taken care

by implementing another sensor. Also, the rate of water

input must always be equal to or greater than the rate of

water output. To make this happen we could use a speed

regulator. If these issues are taken care of then a more

efficient and reliable performance can be achieved. 26

REFERENCES [1] Joydeep Kumar Chakraborty, “Water Level Controller”

[2] Rex Niedermeyer, "Aquarium Water Pumps"

[3] Kevin R. Sullivan, “Understanding Relays”, Professor

of Automotive Technology, Skyline College

[4] 74F00 Quad 2-input NAND gate datasheet, Philips

Corporation

[5] Ward, Jack (2004), the 555Timer IC.

[6] Vardalas, John, Twists and Turns in the Development

of Transistor, IEEE-USA Today’s Engineer, May 2003.